Conventional dense graded thin overlays can be placed on structurally deficient surfaces since they offer significant structural improvement.

• A. Sometimes
• B. Not recommended
• C. True
• D. False

Answer: (D)

Thin overlays are a surface treatment, not a structural fix. They mainly improve ride quality, seal minor cracks, and restore a smooth wearing surface, but they do not restore the load-carrying capacity of a pavement with serious base or subbase problems. When the underlying structure is deficient, adding a shallow layer can’t compensate for the weak foundation and can even trap moisture or allow cracking to reflect through the new layer, leading to premature failure. So conventional dense graded thin overlays should not be expected to provide significant structural improvement on structurally deficient pavements; deeper repairs or rehabilitation of the base and structure are required instead.